Summary/Abstract The primary objective of this research is to develop new technology to characterize personal exposure to airborne metals in the workplace. The secondary objective is to improve upon the state-of-the-art in both sensitivity and time-resolution of airborne metals exposure assessment. Key to this effort is an innovative technology called microfluidic paper analytical devices (PADs) that integrate sampling with analysis in a low cost, high sensitivity format. Our central hypothesis is that PADs can be integrated into personal aerosol samplers for quantification of personal exposure to airborne metals with sampling and analysis times of less than one hour. To test this hypothesis, we propose the following specific aims: (1) Construct a single-analyte microfluidic paper analytical device (PAD) for metal analysis that is compatible with existing, size-selective personal aerosol samplers; (2) Construct a multi-analyte PAD for analysis of Pb, Cu, Mn, and Ni concentrations in air; (3) Validate the performance of the multi-analyte PAD in the field. Successful completion of the above aims will provide industrial hygienists with a sensitive, in-situ technique to assess airborne metal hazards in the workplace. Such technology represents a paradigm shift in the field of exposure assessment, as it has the potential to replace the traditional practice of sample shipment and laboratory analysis (both of which are time and resource intensive) with a direct, field analysis technique with improved sensitivity and time-resolution. This research contributes to the National Occupational Research Agenda (NORA) by developing a new and inexpensive instrumentation (a cross-sector theme) for assessing worker exposure (a cross-sector theme) to airborne metals (affecting the transportation/utilities, manufacturing, and construction sectors). Chemical analysis of a PAD sample is expected to be at least an order of magnitude less expensive (around 5$ per sample) than analysis with traditional ICP-MS or AES techniques. Furthermore, integrating the PAD into existing aerosol sampling devices (i.e., inhalable filter samplers) will enhance its acceptance by practicing occupational health professionals. This technology may open the door to a new realm of aerosol exposure assessment, as PADs can be adapted to detect and quantify many metal, organic, or inorganic compounds.